This is a continuation application for HL-14237 SCOR: Arteriosclerosis Center. It is planned to continue and extend the present program of fundamental and clinical research on the structure and function of lipoproteins, with emphasis throughout on the structure, synthesis, secretion, interaction with cell surfaces and catabolism of plasma lipoproteins in experimental animals and model systems. It also includes detailed analysis of data collected on the prevalence and detailed characterization of hyperlipoproteinemia, new research on genetic and non-genetic factors affecting the structure and composition of apolipoproteins and research on the treatment of familial hyperbetalipoproteinemia and the effect of drug treatment of hyperlipoproteinemias upon apolipoprotein composition. The total program includes core laboratories and administrative facilities and six individual research projects: 1) Role of apolipoproteins in lipoprotein catabolism; 2) Interactions of triglyceride- and cholesterol-rich lipoprotein particles with the vascular surface; 3) Structure of lipoproteins and apolipoproteins; 4) Synthesis and secretion of normal and abnormal plasma lipoproteins; 5) Genetic and non-genetic determinants of apolipoprotein variability in lipoproteins; 6) Treatment of familial hyperbetalipoproteinemia.